<p>
  <button type="button" class="btn btn-primary btn-sm"
          (click)="isOpen = !isOpen">Toggle last panel
  </button>
</p>

<accordion>
  <accordion-group heading="Content 1">
    <p>accordion 1</p>
  </accordion-group>
  <accordion-group heading="Content 2">
    <p>accordion 2</p>
  </accordion-group>
  <accordion-group [isOpen]="isOpen" heading="Last panel">
    <p>accordion 3</p>
  </accordion-group>
</accordion>
